Buy yourself a small notebook and a pen that you can carry with you wherever you go. It has to be little enough for you to be able to slip it into your back pocket or carrying bag.
Ask some of your friends for their input on how you present yourself to others. Tell them that you want them to be honest about your faults as well as your virtues. Write down their thoughts and observances about you, even the ones that you don't agree with.
Take out your notebook throughout the day and write down the different events that you experienced and how you reacted to them. Details are important because they reveal how certain things that people say or do, their facial expressions and body language, affect you. After a particular exciting or upsetting situation, make sure to write down everything right away so you don't forget the details.
Testing your personality traits with self help depends on if you don't react as much as how you react to certain situations. Everyone has his quirks. Something that may not upset you could infuriate your friend and vice versus. In order to understand yourself completely, you have to consider every aspect of who you are. This also includes thinking about what you are not
Repeat Steps 1-4 for at least a month. During that that time you may notice that different aspects of your demeanor have already changed. This is because you are becoming more conscious of who you are and more sure about who you'd like to be. If you recognize any signs of disorders or other serious emotional issues, make sure to seek professional help immediatly. There are many treatments available that can be beneficial to improving your life. See resource section below for more information.
Give yourself a weekend alone to go over all of your notes. Think about what your strengths and weaknesses are. Once you have isolated what you want to change, see the resource section below for great advice articles on how to make the change.